In a conventional ultrasonic diagnosing apparatus, it has been known that the center of a spatial energy profile of an ultrasound beam is substantially flattened at the target position (see Patent document 1, for example). Thus, as shown in FIG. 38 for example, the final shape of waveform outputted from all of the transducer elements 106 is a composite waveform 107, which is determined by combining at least two predetermined component waveforms 201.
Preferably, the composite waveforms 107 of respective channels are not completely the same, and as shown in FIG. 39, they are formed as distinct component waveforms 201 corresponding to a plurality of separate ultrasound beams 202a, 202b, 202c . . . that are outputted substantially to all of predetermined regions over the same period. A fat TX beam 104 (hereinafter referred to as a trapezoidal transmission beam) is formed by the superimposition of these component waveforms 201.    Patent document 1: JP 2006-506158 A (paragraphs 0014, 0033, 0043, FIGS. 2, 3, 21)